/*! *****************************************************************************
Copyright (C) Microsoft. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use
this file except in compliance with the License. You may obtain a copy of the
License at http://www.apache.org/licenses/LICENSE-2.0

THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
MERCHANTABLITY OR NON-INFRINGEMENT.

See the Apache Version 2.0 License for specific language governing permissions
and limitations under the License.
***************************************************************************** */
// namespace Reflect {
    "use strict";

    type object = {}; // placeholder until https://github.com/Microsoft/TypeScript/pull/12501

    type HashMap<V> = Record<string, V>;

    interface BufferLike {
        [offset: number]: number;
        length: number;
    }

    type IteratorResult<T> = { value: T, done: false } | { value: never, done: true };

    interface Iterator<T> {
        next(value?: any): IteratorResult<T>;
        throw?(value: any): IteratorResult<T>;
        return?(value?: T): IteratorResult<T>;
    }

    interface Iterable<T> {
        "@@iterator"(): Iterator<T>;
    }

    interface IterableIterator<T> extends Iterator<T> {
        "@@iterator"(): IterableIterator<T>;
    }

    interface Map<K, V> extends Iterable<[K, V]> {
        size: number;
        has(key: K): boolean;
        get(key: K): V;
        set(key: K, value?: V): this;
        delete(key: K): boolean;
        clear(): void;
        keys(): IterableIterator<K>;
        values(): IterableIterator<V>;
        entries(): IterableIterator<[K, V]>;
    }

    interface MapConstructor {
        new (): Map<any, any>;
        new <K, V>(): Map<K, V>;
        prototype: Map<any, any>;
    }

    interface Set<T> extends Iterable<T> {
        size: number;
        has(value: T): boolean;
        add(value: T): this;
        delete(value: T): boolean;
        clear(): void;
        keys(): IterableIterator<T>;
        values(): IterableIterator<T>;
        entries(): IterableIterator<[T, T]>;
    }

    interface SetConstructor {
        new (): Set<any>;
        new <T>(): Set<T>;
        prototype: Set<any>;
    }

    interface WeakMap<K, V> {
        clear(): void;
        delete(key: K): boolean;
        get(key: K): V;
        has(key: K): boolean;
        set(key: K, value?: V): WeakMap<K, V>;
    }

    interface WeakMapConstructor {
        new (): WeakMap<any, any>;
        new <K, V>(): WeakMap<K, V>;
        prototype: WeakMap<any, any>;
    }

    type MemberDecorator = <T>(target: Object, propertyKey: string | symbol, descriptor?: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T> | void;

    declare const Symbol: { iterator: symbol, toPrimitive: symbol };
    declare const Set: SetConstructor;
    declare const WeakMap: WeakMapConstructor;
    declare const Map: MapConstructor;
    declare const global: any;
    declare const crypto: Crypto;
    declare const msCrypto: Crypto;

    const hasOwn = Object.prototype.hasOwnProperty;

    // feature test for Object.create support
    const supportsCreate = typeof Object.create === "function";

    // feature test for __proto__ support
    const supportsProto = { __proto__: [] } instanceof Array;

    // feature test for Symbol support
    const supportsSymbol = typeof Symbol === "function";
    const toPrimitiveSymbol = supportsSymbol && typeof Symbol.toPrimitive !== "undefined" ? Symbol.toPrimitive : "@@toPrimitive";
    const iteratorSymbol = supportsSymbol && typeof Symbol.iterator !== "undefined" ? Symbol.iterator : "@@iterator";

    // create an object in dictionary mode (a.k.a. "slow" mode in v8)
    const createDictionary =
        supportsCreate ? <V>() => MakeDictionary(Object.create(null) as HashMap<V>) :
            supportsProto ? <V>() => MakeDictionary({ __proto__: null as any } as HashMap<V>) :
                <V>() => MakeDictionary({} as HashMap<V>);

    namespace HashMap {
        const downLevel = !supportsCreate && !supportsProto;
        export const has = downLevel
            ? <V>(map: HashMap<V>, key: string | number | symbol) => hasOwn.call(map, key)
            : <V>(map: HashMap<V>, key: string | number | symbol) => key in map;
        export const get = downLevel
            ? <V>(map: HashMap<V>, key: string | number | symbol): V | undefined => hasOwn.call(map, key) ? map[key] : undefined
            : <V>(map: HashMap<V>, key: string | number | symbol): V | undefined => map[key];
    }

    // Load global or shim versions of Map, Set, and WeakMap
    const functionPrototype = Object.getPrototypeOf(Function);
    const _Map: typeof Map = typeof Map === "function" && typeof Map.prototype.entries === "function" ? Map : CreateMapPolyfill();
    const _Set: typeof Set = typeof Set === "function" && typeof Set.prototype.entries === "function" ? Set : CreateSetPolyfill();
    const _WeakMap: typeof WeakMap = typeof WeakMap === "function" ? WeakMap : CreateWeakMapPolyfill();

    // [[Metadata]] internal slot
    const Metadata = new _WeakMap<object, Map<string | symbol | undefined, Map<any, any>>>();

    /**
      * Applies a set of decorators to a target object.
      * @param decorators An array of decorators.
      * @param target The target object.
      * @returns The result of applying the provided decorators.
      * @remarks Decorators are applied in reverse order of their positions in the array.
      * @example
      *
      *     class Example { }
      *
      *     // constructor
      *     Example = Reflect.decorate(decoratorsArray, Example);
      *
      */
    export function decorate(decorators: ClassDecorator[], target: Function): Function;

    /**
      * Applies a set of decorators to a property of a target object.
      * @param decorators An array of decorators.
      * @param target The target object.
      * @param targetKey The property key to decorate.
      * @param targetDescriptor A property descriptor
      * @remarks Decorators are applied in reverse order.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         static staticMethod() { }
      *         method() { }
      *     }
      *
      *     // property (on constructor)
      *     Reflect.decorate(decoratorsArray, Example, "staticProperty");
      *
      *     // property (on prototype)
      *     Reflect.decorate(decoratorsArray, Example.prototype, "property");
      *
      *     // method (on constructor)
      *     Object.defineProperty(Example, "staticMethod",
      *         Reflect.decorate(decoratorsArray, Example, "staticMethod",
      *             Object.getOwnPropertyDescriptor(Example, "staticMethod")));
      *
      *     // method (on prototype)
      *     Object.defineProperty(Example.prototype, "method",
      *         Reflect.decorate(decoratorsArray, Example.prototype, "method",
      *             Object.getOwnPropertyDescriptor(Example.prototype, "method")));
      *
      */
    export function decorate(decorators: (PropertyDecorator | MethodDecorator)[], target: object, targetKey: string | symbol, targetDescriptor?: PropertyDescriptor | null): PropertyDescriptor | undefined;

    /**
      * Applies a set of decorators to a property of a target object.
      * @param decorators An array of decorators.
      * @param target The target object.
      * @param targetKey The property key to decorate.
      * @param targetDescriptor A property descriptor
      * @remarks Decorators are applied in reverse order.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         static staticMethod() { }
      *         method() { }
      *     }
      *
      *     // property (on constructor)
      *     Reflect.decorate(decoratorsArray, Example, "staticProperty");
      *
      *     // property (on prototype)
      *     Reflect.decorate(decoratorsArray, Example.prototype, "property");
      *
      *     // method (on constructor)
      *     Object.defineProperty(Example, "staticMethod",
      *         Reflect.decorate(decoratorsArray, Example, "staticMethod",
      *             Object.getOwnPropertyDescriptor(Example, "staticMethod")));
      *
      *     // method (on prototype)
      *     Object.defineProperty(Example.prototype, "method",
      *         Reflect.decorate(decoratorsArray, Example.prototype, "method",
      *             Object.getOwnPropertyDescriptor(Example.prototype, "method")));
      *
      */
    export function decorate(decorators: (PropertyDecorator | MethodDecorator)[], target: object, targetKey: string | symbol, targetDescriptor: PropertyDescriptor): PropertyDescriptor;

    /**
      * Applies a set of decorators to a property of a target object.
      * @param decorators An array of decorators.
      * @param target The target object.
      * @param targetKey (Optional) The property key to decorate.
      * @param targetDescriptor (Optional) The property descriptor for the target key
      * @remarks Decorators are applied in reverse order.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         constructor(p) { }
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // constructor
      *     Example = Reflect.decorate(decoratorsArray, Example);
      *
      *     // property (on constructor)
      *     Reflect.decorate(decoratorsArray, Example, "staticProperty");
      *
      *     // property (on prototype)
      *     Reflect.decorate(decoratorsArray, Example.prototype, "property");
      *
      *     // method (on constructor)
      *     Object.defineProperty(Example, "staticMethod",
      *         Reflect.decorate(decoratorsArray, Example, "staticMethod",
      *             Object.getOwnPropertyDescriptor(Example, "staticMethod")));
      *
      *     // method (on prototype)
      *     Object.defineProperty(Example.prototype, "method",
      *         Reflect.decorate(decoratorsArray, Example.prototype, "method",
      *             Object.getOwnPropertyDescriptor(Example.prototype, "method")));
      *
      */
    export function decorate(decorators: (ClassDecorator | MemberDecorator)[], target: object, targetKey?: string | symbol, targetDescriptor?: PropertyDescriptor | null): PropertyDescriptor | Function | undefined {
        if (!IsUndefined(targetKey)) {
            if (!IsArray(decorators)) throw new TypeError();
            if (!IsObject(target)) throw new TypeError();
            if (!IsObject(targetDescriptor) && !IsUndefined(targetDescriptor) && !IsNull(targetDescriptor)) throw new TypeError();
            if (IsNull(targetDescriptor)) targetDescriptor = undefined;
            targetKey = ToPropertyKey(targetKey);
            return DecorateProperty(<MemberDecorator[]>decorators, target, targetKey, targetDescriptor);
        }
        else {
            if (!IsArray(decorators)) throw new TypeError();
            if (!IsConstructor(target)) throw new TypeError();
            return DecorateConstructor(<ClassDecorator[]>decorators, <Function>target);
        }
    }

    /**
      * A default metadata decorator factory that can be used on a class, class member, or parameter.
      * @param metadataKey The key for the metadata entry.
      * @param metadataValue The value for the metadata entry.
      * @returns A decorator function.
      * @remarks
      * If `metadataKey` is already defined for the target and target key, the
      * metadataValue for that key will be overwritten.
      * @example
      *
      *     // constructor
      *     @Reflect.metadata(key, value)
      *     class Example {
      *     }
      *
      *     // property (on constructor, TypeScript only)
      *     class Example {
      *         @Reflect.metadata(key, value)
      *         static staticProperty;
      *     }
      *
      *     // property (on prototype, TypeScript only)
      *     class Example {
      *         @Reflect.metadata(key, value)
      *         property;
      *     }
      *
      *     // method (on constructor)
      *     class Example {
      *         @Reflect.metadata(key, value)
      *         static staticMethod() { }
      *     }
      *
      *     // method (on prototype)
      *     class Example {
      *         @Reflect.metadata(key, value)
      *         method() { }
      *     }
      *
      */
    export function metadata(metadataKey: any, metadataValue: any) {
        function decorator(target: Function): void;
        function decorator(target: object, targetKey: string | symbol): void;
        function decorator(target: object, targetKey?: string | symbol): void {
            if (!IsUndefined(targetKey)) {
                if (!IsObject(target)) throw new TypeError();
                targetKey = ToPropertyKey(targetKey);
                OrdinaryDefineOwnMetadata(metadataKey, metadataValue, target, targetKey);
            }
            else {
                if (!IsConstructor(target)) throw new TypeError();
                OrdinaryDefineOwnMetadata(metadataKey, metadataValue, target, /*targetKey*/ undefined);
            }
        }
        return decorator;
    }

    /**
      * Define a unique metadata entry on the target.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param metadataValue A value that contains attached metadata.
      * @param target The target object on which to define metadata.
      * @example
      *
      *     class Example {
      *     }
      *
      *     // constructor
      *     Reflect.defineMetadata("custom:annotation", options, Example);
      *
      *     // decorator factory as metadata-producing annotation.
      *     function MyAnnotation(options): ClassDecorator {
      *         return target => Reflect.defineMetadata("custom:annotation", options, target);
      *     }
      *
      */
    export function defineMetadata(metadataKey: any, metadataValue: any, target: object): void;

    /**
      * Define a unique metadata entry on the target.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param metadataValue A value that contains attached metadata.
      * @param target The target object on which to define metadata.
      * @param targetKey The property key for the target.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // property (on constructor)
      *     Reflect.defineMetadata("custom:annotation", Number, Example, "staticProperty");
      *
      *     // property (on prototype)
      *     Reflect.defineMetadata("custom:annotation", Number, Example.prototype, "property");
      *
      *     // method (on constructor)
      *     Reflect.defineMetadata("custom:annotation", Number, Example, "staticMethod");
      *
      *     // method (on prototype)
      *     Reflect.defineMetadata("custom:annotation", Number, Example.prototype, "method");
      *
      *     // decorator factory as metadata-producing annotation.
      *     function MyAnnotation(options): PropertyDecorator {
      *         return (target, key) => Reflect.defineMetadata("custom:annotation", options, target, key);
      *     }
      *
      */
    export function defineMetadata(metadataKey: any, metadataValue: any, target: object, targetKey: string | symbol): void;

    /**
      * Define a unique metadata entry on the target.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param metadataValue A value that contains attached metadata.
      * @param target The target object on which to define metadata.
      * @param targetKey (Optional) The property key for the target.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         constructor(p) { }
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // constructor
      *     Reflect.defineMetadata("custom:annotation", options, Example);
      *
      *     // property (on constructor)
      *     Reflect.defineMetadata("custom:annotation", options, Example, "staticProperty");
      *
      *     // property (on prototype)
      *     Reflect.defineMetadata("custom:annotation", options, Example.prototype, "property");
      *
      *     // method (on constructor)
      *     Reflect.defineMetadata("custom:annotation", options, Example, "staticMethod");
      *
      *     // method (on prototype)
      *     Reflect.defineMetadata("custom:annotation", options, Example.prototype, "method");
      *
      *     // decorator factory as metadata-producing annotation.
      *     function MyAnnotation(options): Decorator {
      *         return (target, key?) => Reflect.defineMetadata("custom:annotation", options, target, key);
      *     }
      *
      */
    export function defineMetadata(metadataKey: any, metadataValue: any, target: object, targetKey?: string | symbol): void {
        if (!IsObject(target)) throw new TypeError();
        if (!IsUndefined(targetKey)) targetKey = ToPropertyKey(targetKey);
        return OrdinaryDefineOwnMetadata(metadataKey, metadataValue, target, targetKey);
    }

    /**
      * Gets a value indicating whether the target object or its prototype chain has the provided metadata key defined.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @returns `true` if the metadata key was defined on the target object or its prototype chain; otherwise, `false`.
      * @example
      *
      *     class Example {
      *     }
      *
      *     // constructor
      *     result = Reflect.hasMetadata("custom:annotation", Example);
      *
      */
    export function hasMetadata(metadataKey: any, target: object): boolean;

    /**
      * Gets a value indicating whether the target object or its prototype chain has the provided metadata key defined.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @param targetKey The property key for the target.
      * @returns `true` if the metadata key was defined on the target object or its prototype chain; otherwise, `false`.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // property (on constructor)
      *     result = Reflect.hasMetadata("custom:annotation", Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.hasMetadata("custom:annotation", Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.hasMetadata("custom:annotation", Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.hasMetadata("custom:annotation", Example.prototype, "method");
      *
      */
    export function hasMetadata(metadataKey: any, target: object, targetKey: string | symbol): boolean;

    /**
      * Gets a value indicating whether the target object or its prototype chain has the provided metadata key defined.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @param targetKey (Optional) The property key for the target.
      * @returns `true` if the metadata key was defined on the target object or its prototype chain; otherwise, `false`.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         constructor(p) { }
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // constructor
      *     result = Reflect.hasMetadata("custom:annotation", Example);
      *
      *     // property (on constructor)
      *     result = Reflect.hasMetadata("custom:annotation", Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.hasMetadata("custom:annotation", Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.hasMetadata("custom:annotation", Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.hasMetadata("custom:annotation", Example.prototype, "method");
      *
      */
    export function hasMetadata(metadataKey: any, target: object, targetKey?: string | symbol): boolean {
        if (!IsObject(target)) throw new TypeError();
        if (!IsUndefined(targetKey)) targetKey = ToPropertyKey(targetKey);
        return OrdinaryHasMetadata(metadataKey, target, targetKey);
    }

    /**
      * Gets a value indicating whether the target object has the provided metadata key defined.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @returns `true` if the metadata key was defined on the target object; otherwise, `false`.
      * @example
      *
      *     class Example {
      *     }
      *
      *     // constructor
      *     result = Reflect.hasOwnMetadata("custom:annotation", Example);
      *
      */
    export function hasOwnMetadata(metadataKey: any, target: object): boolean;

    /**
      * Gets a value indicating whether the target object has the provided metadata key defined.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @param targetKey The property key for the target.
      * @returns `true` if the metadata key was defined on the target object; otherwise, `false`.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // property (on constructor)
      *     result = Reflect.hasOwnMetadata("custom:annotation", Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.hasOwnMetadata("custom:annotation", Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.hasOwnMetadata("custom:annotation", Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.hasOwnMetadata("custom:annotation", Example.prototype, "method");
      *
      */
    export function hasOwnMetadata(metadataKey: any, target: object, targetKey: string | symbol): boolean;

    /**
      * Gets a value indicating whether the target object has the provided metadata key defined.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @param targetKey (Optional) The property key for the target.
      * @returns `true` if the metadata key was defined on the target object; otherwise, `false`.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         constructor(p) { }
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // constructor
      *     result = Reflect.hasOwnMetadata("custom:annotation", Example);
      *
      *     // property (on constructor)
      *     result = Reflect.hasOwnMetadata("custom:annotation", Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.hasOwnMetadata("custom:annotation", Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.hasOwnMetadata("custom:annotation", Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.hasOwnMetadata("custom:annotation", Example.prototype, "method");
      *
      */
    export function hasOwnMetadata(metadataKey: any, target: object, targetKey?: string | symbol): boolean {
        if (!IsObject(target)) throw new TypeError();
        if (!IsUndefined(targetKey)) targetKey = ToPropertyKey(targetKey);
        return OrdinaryHasOwnMetadata(metadataKey, target, targetKey);
    }

    /**
      * Gets the metadata value for the provided metadata key on the target object or its prototype chain.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
      * @example
      *
      *     class Example {
      *     }
      *
      *     // constructor
      *     result = Reflect.getMetadata("custom:annotation", Example);
      *
      */
    export function getMetadata(metadataKey: any, target: object): any;

    /**
      * Gets the metadata value for the provided metadata key on the target object or its prototype chain.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @param targetKey The property key for the target.
      * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // property (on constructor)
      *     result = Reflect.getMetadata("custom:annotation", Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.getMetadata("custom:annotation", Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.getMetadata("custom:annotation", Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.getMetadata("custom:annotation", Example.prototype, "method");
      *
      */
    export function getMetadata(metadataKey: any, target: object, targetKey: string | symbol): any;

    /**
      * Gets the metadata value for the provided metadata key on the target object or its prototype chain.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @param targetKey (Optional) The property key for the target.
      * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         constructor(p) { }
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // constructor
      *     result = Reflect.getMetadata("custom:annotation", Example);
      *
      *     // property (on constructor)
      *     result = Reflect.getMetadata("custom:annotation", Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.getMetadata("custom:annotation", Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.getMetadata("custom:annotation", Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.getMetadata("custom:annotation", Example.prototype, "method");
      *
      */
    export function getMetadata(metadataKey: any, target: object, targetKey?: string | symbol): any {
        if (!IsObject(target)) throw new TypeError();
        if (!IsUndefined(targetKey)) targetKey = ToPropertyKey(targetKey);
        return OrdinaryGetMetadata(metadataKey, target, targetKey);
    }

    /**
      * Gets the metadata value for the provided metadata key on the target object.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
      * @example
      *
      *     class Example {
      *     }
      *
      *     // constructor
      *     result = Reflect.getOwnMetadata("custom:annotation", Example);
      *
      */
    export function getOwnMetadata(metadataKey: any, target: object): any;

    /**
      * Gets the metadata value for the provided metadata key on the target object.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @param targetKey The property key for the target.
      * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // property (on constructor)
      *     result = Reflect.getOwnMetadata("custom:annotation", Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.getOwnMetadata("custom:annotation", Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.getOwnMetadata("custom:annotation", Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.getOwnMetadata("custom:annotation", Example.prototype, "method");
      *
      */
    export function getOwnMetadata(metadataKey: any, target: object, targetKey: string | symbol): any;

    /**
      * Gets the metadata value for the provided metadata key on the target object.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @param targetKey (Optional) The property key for the target.
      * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         constructor(p) { }
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // constructor
      *     result = Reflect.getOwnMetadata("custom:annotation", Example);
      *
      *     // property (on constructor)
      *     result = Reflect.getOwnMetadata("custom:annotation", Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.getOwnMetadata("custom:annotation", Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.getOwnMetadata("custom:annotation", Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.getOwnMetadata("custom:annotation", Example.prototype, "method");
      *
      */
    export function getOwnMetadata(metadataKey: any, target: object, targetKey?: string | symbol): any {
        if (!IsObject(target)) throw new TypeError();
        if (!IsUndefined(targetKey)) targetKey = ToPropertyKey(targetKey);
        return OrdinaryGetOwnMetadata(metadataKey, target, targetKey);
    }

    /**
      * Gets the metadata keys defined on the target object or its prototype chain.
      * @param target The target object on which the metadata is defined.
      * @returns An array of unique metadata keys.
      * @example
      *
      *     class Example {
      *     }
      *
      *     // constructor
      *     result = Reflect.getMetadataKeys(Example);
      *
      */
    export function getMetadataKeys(target: object): any[];

    /**
      * Gets the metadata keys defined on the target object or its prototype chain.
      * @param target The target object on which the metadata is defined.
      * @param targetKey The property key for the target.
      * @returns An array of unique metadata keys.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // property (on constructor)
      *     result = Reflect.getMetadataKeys(Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.getMetadataKeys(Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.getMetadataKeys(Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.getMetadataKeys(Example.prototype, "method");
      *
      */
    export function getMetadataKeys(target: object, targetKey: string | symbol): any[];

    /**
      * Gets the metadata keys defined on the target object or its prototype chain.
      * @param target The target object on which the metadata is defined.
      * @param targetKey (Optional) The property key for the target.
      * @returns An array of unique metadata keys.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         constructor(p) { }
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // constructor
      *     result = Reflect.getMetadataKeys(Example);
      *
      *     // property (on constructor)
      *     result = Reflect.getMetadataKeys(Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.getMetadataKeys(Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.getMetadataKeys(Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.getMetadataKeys(Example.prototype, "method");
      *
      */
    export function getMetadataKeys(target: object, targetKey?: string | symbol): any[] {
        if (!IsObject(target)) throw new TypeError();
        if (!IsUndefined(targetKey)) targetKey = ToPropertyKey(targetKey);
        return OrdinaryMetadataKeys(target, targetKey);
    }

    /**
      * Gets the unique metadata keys defined on the target object.
      * @param target The target object on which the metadata is defined.
      * @returns An array of unique metadata keys.
      * @example
      *
      *     class Example {
      *     }
      *
      *     // constructor
      *     result = Reflect.getOwnMetadataKeys(Example);
      *
      */
    export function getOwnMetadataKeys(target: object): any[];

    /**
      * Gets the unique metadata keys defined on the target object.
      * @param target The target object on which the metadata is defined.
      * @param targetKey The property key for the target.
      * @returns An array of unique metadata keys.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // property (on constructor)
      *     result = Reflect.getOwnMetadataKeys(Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.getOwnMetadataKeys(Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.getOwnMetadataKeys(Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.getOwnMetadataKeys(Example.prototype, "method");
      *
      */
    export function getOwnMetadataKeys(target: object, targetKey: string | symbol): any[];

    /**
      * Gets the unique metadata keys defined on the target object.
      * @param target The target object on which the metadata is defined.
      * @param targetKey (Optional) The property key for the target.
      * @returns An array of unique metadata keys.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         constructor(p) { }
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // constructor
      *     result = Reflect.getOwnMetadataKeys(Example);
      *
      *     // property (on constructor)
      *     result = Reflect.getOwnMetadataKeys(Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.getOwnMetadataKeys(Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.getOwnMetadataKeys(Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.getOwnMetadataKeys(Example.prototype, "method");
      *
      */
    export function getOwnMetadataKeys(target: object, targetKey?: string | symbol): any[] {
        if (!IsObject(target)) throw new TypeError();
        if (!IsUndefined(targetKey)) targetKey = ToPropertyKey(targetKey);
        return OrdinaryOwnMetadataKeys(target, targetKey);
    }

    /**
      * Deletes the metadata entry from the target object with the provided key.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @returns `true` if the metadata entry was found and deleted; otherwise, false.
      * @example
      *
      *     class Example {
      *     }
      *
      *     // constructor
      *     result = Reflect.deleteMetadata("custom:annotation", Example);
      *
      */
    export function deleteMetadata(metadataKey: any, target: object): boolean;

    /**
      * Deletes the metadata entry from the target object with the provided key.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @param targetKey The property key for the target.
      * @returns `true` if the metadata entry was found and deleted; otherwise, false.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // property (on constructor)
      *     result = Reflect.deleteMetadata("custom:annotation", Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.deleteMetadata("custom:annotation", Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.deleteMetadata("custom:annotation", Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.deleteMetadata("custom:annotation", Example.prototype, "method");
      *
      */
    export function deleteMetadata(metadataKey: any, target: object, targetKey: string | symbol): boolean;

    /**
      * Deletes the metadata entry from the target object with the provided key.
      * @param metadataKey A key used to store and retrieve metadata.
      * @param target The target object on which the metadata is defined.
      * @param targetKey (Optional) The property key for the target.
      * @returns `true` if the metadata entry was found and deleted; otherwise, false.
      * @example
      *
      *     class Example {
      *         // property declarations are not part of ES6, though they are valid in TypeScript:
      *         // static staticProperty;
      *         // property;
      *
      *         constructor(p) { }
      *         static staticMethod(p) { }
      *         method(p) { }
      *     }
      *
      *     // constructor
      *     result = Reflect.deleteMetadata("custom:annotation", Example);
      *
      *     // property (on constructor)
      *     result = Reflect.deleteMetadata("custom:annotation", Example, "staticProperty");
      *
      *     // property (on prototype)
      *     result = Reflect.deleteMetadata("custom:annotation", Example.prototype, "property");
      *
      *     // method (on constructor)
      *     result = Reflect.deleteMetadata("custom:annotation", Example, "staticMethod");
      *
      *     // method (on prototype)
      *     result = Reflect.deleteMetadata("custom:annotation", Example.prototype, "method");
      *
      */
    export function deleteMetadata(metadataKey: any, target: object, targetKey?: string | symbol): boolean {
        // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#deletemetadata-metadatakey-p-
        if (!IsObject(target)) throw new TypeError();
        if (!IsUndefined(targetKey)) targetKey = ToPropertyKey(targetKey);
        const metadataMap = GetOrCreateMetadataMap(target, targetKey, /*create*/ false);
        if (IsUndefined(metadataMap)) return false;
        if (!metadataMap.delete(metadataKey)) return false;
        if (metadataMap.size > 0) return true;
        const targetMetadata = Metadata.get(target);
        targetMetadata.delete(targetKey);
        if (targetMetadata.size > 0) return true;
        Metadata.delete(target);
        return true;
    }

    function DecorateConstructor(decorators: ClassDecorator[], target: Function): Function {
        for (let i = decorators.length - 1; i >= 0; --i) {
            const decorator = decorators[i];
            const decorated = decorator(target);
            if (!IsUndefined(decorated) && !IsNull(decorated)) {
                if (!IsConstructor(decorated)) throw new TypeError();
                target = <Function>decorated;
            }
        }
        return target;
    }

    function DecorateProperty(decorators: MemberDecorator[], target: object, propertyKey: string | symbol, descriptor: PropertyDescriptor | undefined): PropertyDescriptor | undefined {
        for (let i = decorators.length - 1; i >= 0; --i) {
            const decorator = decorators[i];
            const decorated = decorator(target, propertyKey, descriptor);
            if (!IsUndefined(decorated) && !IsNull(decorated)) {
                if (!IsObject(decorated)) throw new TypeError();
                descriptor = <PropertyDescriptor>decorated;
            }
        }
        return descriptor;
    }

    // Metadata Proposal
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md

    // Operations on Objects
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#operations-on-objects

    // GetOrCreateMetadataMap(O, P, Create)
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#getorcreatemetadatamap--o-p-create-
    function GetOrCreateMetadataMap(O: object, P: string | symbol | undefined, Create: true): Map<any, any>;
    function GetOrCreateMetadataMap(O: object, P: string | symbol | undefined, Create: false): Map<any, any> | undefined;
    function GetOrCreateMetadataMap(O: object, P: string | symbol | undefined, Create: boolean): Map<any, any> | undefined {
        let targetMetadata = Metadata.get(O);
        if (IsUndefined(targetMetadata)) {
            if (!Create) return undefined;
            targetMetadata = new _Map<string | symbol | undefined, Map<any, any>>();
            Metadata.set(O, targetMetadata);
        }
        let metadataMap = targetMetadata.get(P);
        if (IsUndefined(metadataMap)) {
            if (!Create) return undefined;
            metadataMap = new _Map<any, any>();
            targetMetadata.set(P, metadataMap);
        }
        return metadataMap;
    }

    // Ordinary Object Internal Methods and Internal Slots
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#ordinary-object-internal-methods-and-internal-slots

    // OrdinaryHasMetadata(MetadataKey, O, P)
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#ordinaryhasmetadata--metadatakey-o-p-
    function OrdinaryHasMetadata(MetadataKey: any, O: object, P: string | symbol | undefined): boolean {
        const hasOwn = OrdinaryHasOwnMetadata(MetadataKey, O, P);
        if (hasOwn) return true;
        const parent = OrdinaryGetPrototypeOf(O);
        if (!IsNull(parent)) return OrdinaryHasMetadata(MetadataKey, parent, P);
        return false;
    }

    // OrdinaryHasOwnMetadata(MetadataKey, O, P)
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#ordinaryhasownmetadata--metadatakey-o-p-
    function OrdinaryHasOwnMetadata(MetadataKey: any, O: object, P: string | symbol | undefined): boolean {
        const metadataMap = GetOrCreateMetadataMap(O, P, /*create*/ false);
        if (IsUndefined(metadataMap)) return false;
        return ToBoolean(metadataMap.has(MetadataKey));
    }

    // OrdinaryGetMetadata(MetadataKey, O, P)
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#ordinarygetmetadata--metadatakey-o-p-
    function OrdinaryGetMetadata(MetadataKey: any, O: object, P: string | symbol | undefined): any {
        const hasOwn = OrdinaryHasOwnMetadata(MetadataKey, O, P);
        if (hasOwn) return OrdinaryGetOwnMetadata(MetadataKey, O, P);
        const parent = OrdinaryGetPrototypeOf(O);
        if (!IsNull(parent)) return OrdinaryGetMetadata(MetadataKey, parent, P);
        return undefined;
    }

    // OrdinaryGetOwnMetadata(MetadataKey, O, P)
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#ordinarygetownmetadata--metadatakey-o-p-
    function OrdinaryGetOwnMetadata(MetadataKey: any, O: object, P: string | symbol | undefined): any {
        const metadataMap = GetOrCreateMetadataMap(O, P, /*create*/ false);
        if (IsUndefined(metadataMap)) return undefined;
        return metadataMap.get(MetadataKey);
    }

    // OrdinaryDefineOwnMetadata(MetadataKey, MetadataValue, O, P)
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#ordinarydefineownmetadata--metadatakey-metadatavalue-o-p-
    function OrdinaryDefineOwnMetadata(MetadataKey: any, MetadataValue: any, O: object, P: string | symbol | undefined): void {
        const metadataMap = GetOrCreateMetadataMap(O, P, /*create*/ true);
        metadataMap.set(MetadataKey, MetadataValue);
    }

    // OrdinaryMetadataKeys(O, P)
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#ordinarymetadatakeys--o-p-
    function OrdinaryMetadataKeys(O: object, P: string | symbol | undefined): any[] {
        const ownKeys = OrdinaryOwnMetadataKeys(O, P);
        const parent = OrdinaryGetPrototypeOf(O);
        if (parent === null) return ownKeys;
        const parentKeys = OrdinaryMetadataKeys(parent, P);
        if (parentKeys.length <= 0) return ownKeys;
        if (ownKeys.length <= 0) return parentKeys;
        const set = new _Set<any>();
        const keys: any[] = [];
        for (const key of ownKeys) {
            const hasKey = set.has(key);
            if (!hasKey) {
                set.add(key);
                keys.push(key);
            }
        }
        for (const key of parentKeys) {
            const hasKey = set.has(key);
            if (!hasKey) {
                set.add(key);
                keys.push(key);
            }
        }
        return keys;
    }

    // OrdinaryOwnMetadataKeys(O, P)
    // https://github.com/rbuckton/ReflectDecorators/blob/master/spec/metadata.md#ordinaryownmetadatakeys--o-p-
    function OrdinaryOwnMetadataKeys(O: object, P: string | symbol | undefined): any[] {
        const metadataMap = GetOrCreateMetadataMap(O, P, /*create*/ false);
        const keys: any[] = [];
        if (IsUndefined(metadataMap)) return keys;
        const keysObj = metadataMap.keys();
        const iterator = GetIterator(keysObj);
        while (true) {
            let next = IteratorStep(iterator);
            try {
                if (!next) return keys;
                const nextValue = IteratorValue(next);
                keys.push(nextValue);
            }
            catch (e) {
                try {
                    if (next) {
                        next = false;
                        IteratorClose(iterator);
                    }
                }
                finally {
                    throw e;
                }
            }
            finally {
                if (next) IteratorClose(iterator);
            }
        }
    }

    // ECMAScript Specification
    // https://tc39.github.io/ecma262/

    // 6 ECMAScript Data Typ0es and Values
    // https://tc39.github.io/ecma262/#sec-ecmascript-data-types-and-values
    function Type(x: any): Tag {
        if (x === null) return Tag.Null;
        switch (typeof x) {
            case "undefined": return Tag.Undefined;
            case "boolean": return Tag.Boolean;
            case "string": return Tag.String;
            case "symbol": return Tag.Symbol;
            case "number": return Tag.Number;
            case "object": return x === null ? Tag.Null : Tag.Object;
            default: return Tag.Object;
        }
    }

    // 6.1 ECMAScript Language Types
    // https://tc39.github.io/ecma262/#sec-ecmascript-language-types
    const enum Tag {
        Undefined,
        Null,
        Boolean,
        String,
        Symbol,
        Number,
        Object
    }

    // 6.1.1 The Undefined Type
    // https://tc39.github.io/ecma262/#sec-ecmascript-language-types-undefined-type
    function IsUndefined(x: any): x is undefined {
        return x === undefined;
    }

    // 6.1.2 The Null Type
    // https://tc39.github.io/ecma262/#sec-ecmascript-language-types-null-type
    function IsNull(x: any): x is null {
        return x === null;
    }

    // 6.1.5 The Symbol Type
    // https://tc39.github.io/ecma262/#sec-ecmascript-language-types-symbol-type
    function IsSymbol(x: any): x is symbol {
        return typeof x === "symbol";
    }

    // 6.1.7 The Object Type
    // https://tc39.github.io/ecma262/#sec-object-type
    function IsObject<T>(x: T | undefined | null | boolean | string | symbol | number): x is T {
        return typeof x === "object" ? x !== null : typeof x === "function";
    }

    // 7.1 Type Conversion
    // https://tc39.github.io/ecma262/#sec-type-conversion

    // 7.1.1 ToPrimitive(input [, PreferredType])
    // https://tc39.github.io/ecma262/#sec-toprimitive
    function ToPrimitive(input: any, PreferredType?: Tag): undefined | null | boolean | string | symbol | number {
        switch (Type(input)) {
            case Tag.Undefined: return input;
            case Tag.Null: return input;
            case Tag.Boolean: return input;
            case Tag.String: return input;
            case Tag.Symbol: return input;
            case Tag.Number: return input;
        }
        const hint: "string" | "number" | "default" = PreferredType === Tag.String ? "string" : PreferredType === Tag.Number ? "number" : "default";
        const exoticToPrim = GetMethod(input, toPrimitiveSymbol);
        if (exoticToPrim !== undefined) {
            const result = exoticToPrim.call(input, hint);
            if (IsObject(result)) throw new TypeError();
            return result;
        }
        return OrdinaryToPrimitive(input, hint === "default" ? "number" : hint);
    }

    // 7.1.1.1 OrdinaryToPrimitive(O, hint)
    // https://tc39.github.io/ecma262/#sec-ordinarytoprimitive
    function OrdinaryToPrimitive(O: object, hint: "string" | "number"): undefined | null | boolean | string | symbol | number {
        if (hint === "string") {
            const toString = O.toString;
            if (IsCallable(toString)) {
                const result = toString.call(O);
                if (!IsObject(result)) return result;
            }
            const valueOf = O.valueOf;
            if (IsCallable(valueOf)) {
                const result = valueOf.call(O);
                if (!IsObject(result)) return result;
            }
        }
        else {
            const valueOf = O.valueOf;
            if (IsCallable(valueOf)) {
                const result = valueOf.call(O);
                if (!IsObject(result)) return result;
            }
            const toString = O.toString;
            if (IsCallable(toString)) {
                const result = toString.call(O);
                if (!IsObject(result)) return result;
            }
        }
        throw new TypeError();
    }

    // 7.1.2 ToBoolean(argument)
    // https://tc39.github.io/ecma262/2016/#sec-toboolean
    function ToBoolean(argument: any): boolean {
        return !!argument;
    }

    // 7.1.12 ToString(argument)
    // https://tc39.github.io/ecma262/#sec-tostring
    function ToString(argument: any): string {
        return "" + argument;
    }

    // 7.1.14 ToPropertyKey(argument)
    // https://tc39.github.io/ecma262/#sec-topropertykey
    function ToPropertyKey(argument: any): string | symbol {
        const key = ToPrimitive(argument, Tag.String);
        if (IsSymbol(key)) return key;
        return ToString(key);
    }

    // 7.2 Testing and Comparison Operations
    // https://tc39.github.io/ecma262/#sec-testing-and-comparison-operations

    // 7.2.2 IsArray(argument)
    // https://tc39.github.io/ecma262/#sec-isarray
    function IsArray(argument: any): argument is any[] {
        return Array.isArray
            ? Array.isArray(argument)
            : argument instanceof Object
                ? argument instanceof Array
                : Object.prototype.toString.call(argument) === "[object Array]";
    }

    // 7.2.3 IsCallable(argument)
    // https://tc39.github.io/ecma262/#sec-iscallable
    function IsCallable(argument: any): argument is Function {
        // NOTE: This is an approximation as we cannot check for [[Call]] internal method.
        return typeof argument === "function";
    }

    // 7.2.4 IsConstructor(argument)
    // https://tc39.github.io/ecma262/#sec-isconstructor
    function IsConstructor(argument: any): argument is Function {
        // NOTE: This is an approximation as we cannot check for [[Construct]] internal method.
        return typeof argument === "function";
    }

    // 7.3 Operations on Objects
    // https://tc39.github.io/ecma262/#sec-operations-on-objects

    // 7.3.9 GetMethod(V, P)
    // https://tc39.github.io/ecma262/#sec-getmethod
    function GetMethod(V: any, P: any): Function | undefined {
        const func = V[P];
        if (func === undefined || func === null) return undefined;
        if (!IsCallable(func)) throw new TypeError();
        return func;
    }

    // 7.4 Operations on Iterator Objects
    // https://tc39.github.io/ecma262/#sec-operations-on-iterator-objects

    function GetIterator<T>(obj: Iterable<T>): Iterator<T> {
        const method = GetMethod(obj, iteratorSymbol);
        if (!IsCallable(method)) throw new TypeError(); // from Call
        const iterator = method.call(obj);
        if (!IsObject(iterator)) throw new TypeError();
        return iterator;
    }

    // 7.4.4 IteratorValue(iterResult)
    // https://tc39.github.io/ecma262/2016/#sec-iteratorvalue
    function IteratorValue<T>(iterResult: IteratorResult<T>): T {
        return iterResult.value;
    }

    // 7.4.5 IteratorStep(iterator)
    // https://tc39.github.io/ecma262/#sec-iteratorstep
    function IteratorStep<T>(iterator: Iterator<T>): IteratorResult<T> | false {
        const result = iterator.next();
        return result.done ? false : result;
    }

    // 7.4.6 IteratorClose(iterator, completion)
    // https://tc39.github.io/ecma262/#sec-iteratorclose
    function IteratorClose<T>(iterator: Iterator<T>) {
        const f = iterator["return"];
        if (f) f.call(iterator);
    }

    // 9.1 Ordinary Object Internal Methods and Internal Slots
    // https://tc39.github.io/ecma262/#sec-ordinary-object-internal-methods-and-internal-slots

    // 9.1.1.1 OrdinaryGetPrototypeOf(O)
    // https://tc39.github.io/ecma262/#sec-ordinarygetprototypeof
    function OrdinaryGetPrototypeOf(O: any): object {
        const proto = Object.getPrototypeOf(O);
        if (typeof O !== "function" || O === functionPrototype) return proto;

        // TypeScript doesn't set __proto__ in ES5, as it's non-standard.
        // Try to determine the superclass constructor. Compatible implementations
        // must either set __proto__ on a subclass constructor to the superclass constructor,
        // or ensure each class has a valid `constructor` property on its prototype that
        // points back to the constructor.

        // If this is not the same as Function.[[Prototype]], then this is definately inherited.
        // This is the case when in ES6 or when using __proto__ in a compatible browser.
        if (proto !== functionPrototype) return proto;

        // If the super prototype is Object.prototype, null, or undefined, then we cannot determine the heritage.
        const prototype = O.prototype;
        const prototypeProto = prototype && Object.getPrototypeOf(prototype);
        if (prototypeProto == null || prototypeProto === Object.prototype) return proto;

        // If the constructor was not a function, then we cannot determine the heritage.
        const constructor = prototypeProto.constructor;
        if (typeof constructor !== "function") return proto;

        // If we have some kind of self-reference, then we cannot determine the heritage.
        if (constructor === O) return proto;

        // we have a pretty good guess at the heritage.
        return constructor;
    }

    // naive Map shim
    function CreateMapPolyfill(): MapConstructor {
        const cacheSentinel = {};
        const arraySentinel: any[] = [];

        class MapIterator<K, V, R extends (K | V | [K, V])> implements IterableIterator<R> {
            private _keys: K[];
            private _values: V[];
            private _index = 0;
            private _selector: (key: K, value: V) => R;
            constructor(keys: K[], values: V[], selector: (key: K, value: V) => R) {
                this._keys = keys;
                this._values = values;
                this._selector = selector;
            }
            "@@iterator"() { return this; }
            [iteratorSymbol]() { return this; }
            next(): IteratorResult<R> {
                const index = this._index;
                if (index >= 0 && index < this._keys.length) {
                    const result = this._selector(this._keys[index], this._values[index]);
                    if (index + 1 >= this._keys.length) {
                        this._index = -1;
                        this._keys = arraySentinel;
                        this._values = arraySentinel;
                    }
                    else {
                        this._index++;
                    }
                    return { value: result, done: false };
                }
                return { value: <never>undefined, done: true };
            }
            throw(error: any): IteratorResult<R> {
                if (this._index >= 0) {
                    this._index = -1;
                    this._keys = arraySentinel;
                    this._values = arraySentinel;
                }
                throw error;
            }
            return(value?: R): IteratorResult<R> {
                if (this._index >= 0) {
                    this._index = -1;
                    this._keys = arraySentinel;
                    this._values = arraySentinel;
                }
                return { value: <never>value, done: true };
            }
        }

        return class Map<K, V> {
            private _keys: K[] = [];
            private _values: (V | undefined)[] = [];
            private _cacheKey = cacheSentinel;
            private _cacheIndex = -2;
            get size() { return this._keys.length; }
            has(key: K): boolean { return this._find(key, /*insert*/ false) >= 0; }
            get(key: K): V | undefined {
                const index = this._find(key, /*insert*/ false);
                return index >= 0 ? this._values[index] : undefined;
            }
            set(key: K, value: V): this {
                const index = this._find(key, /*insert*/ true);
                this._values[index] = value;
                return this;
            }
            delete(key: K): boolean {
                const index = this._find(key, /*insert*/ false);
                if (index >= 0) {
                    const size = this._keys.length;
                    for (let i = index + 1; i < size; i++) {
                        this._keys[i - 1] = this._keys[i];
                        this._values[i - 1] = this._values[i];
                    }
                    this._keys.length--;
                    this._values.length--;
                    if (key === this._cacheKey) {
                        this._cacheKey = cacheSentinel;
                        this._cacheIndex = -2;
                    }
                    return true;
                }
                return false;
            }
            clear(): void {
                this._keys.length = 0;
                this._values.length = 0;
                this._cacheKey = cacheSentinel;
                this._cacheIndex = -2;
            }
            keys() { return new MapIterator(this._keys, this._values, getKey); }
            values() { return new MapIterator(this._keys, this._values, getValue); }
            entries() { return new MapIterator(this._keys, this._values, getEntry); }
            "@@iterator"() { return this.entries(); }
            [iteratorSymbol]() { return this.entries(); }
            private _find(key: K, insert?: boolean): number {
                if (this._cacheKey === key) return this._cacheIndex;
                let index = this._keys.indexOf(key);
                if (index < 0 && insert) {
                    index = this._keys.length;
                    this._keys.push(key);
                    this._values.push(undefined);
                }
                return this._cacheKey = key, this._cacheIndex = index;
            }
        };

        function getKey<K, V>(key: K, _: V) {
            return key;
        }

        function getValue<K, V>(_: K, value: V) {
            return value;
        }

        function getEntry<K, V>(key: K, value: V) {
            return [key, value] as [K, V];
        }
    }

    // naive Set shim
    function CreateSetPolyfill(): SetConstructor {
        return class Set<T> {
            private _map = new _Map<any, any>();
            get size() { return this._map.size; }
            has(value: T): boolean { return this._map.has(value); }
            add(value: T): Set<T> { return this._map.set(value, value), this; }
            delete(value: T): boolean { return this._map.delete(value); }
            clear(): void { this._map.clear(); }
            keys() { return this._map.keys(); }
            values() { return this._map.values(); }
            entries() { return this._map.entries(); }
            "@@iterator"() { return this.keys(); }
            [iteratorSymbol]() { return this.keys(); }
        };
    }

    // naive WeakMap shim
    function CreateWeakMapPolyfill(): WeakMapConstructor {
        const UUID_SIZE = 16;
        const keys = createDictionary<boolean>();
        const rootKey = CreateUniqueKey();
        return class WeakMap<K, V> {
            private _key = CreateUniqueKey();
            has(target: K): boolean {
                const table = GetOrCreateWeakMapTable<K>(target, /*create*/ false);
                return table !== undefined ? HashMap.has(table, this._key) : false;
            }
            get(target: K): V {
                const table = GetOrCreateWeakMapTable<K>(target, /*create*/ false);
                return table !== undefined ? HashMap.get(table, this._key) : undefined;
            }
            set(target: K, value: V): WeakMap<K, V> {
                const table = GetOrCreateWeakMapTable<K>(target, /*create*/ true);
                table[this._key] = value;
                return this;
            }
            delete(target: K): boolean {
                const table = GetOrCreateWeakMapTable<K>(target, /*create*/ false);
                return table !== undefined ? delete table[this._key] : false;
            }
            clear(): void {
                // NOTE: not a real clear, just makes the previous data unreachable
                this._key = CreateUniqueKey();
            }
        };

        function CreateUniqueKey(): string {
            let key: string;
            do key = "@@WeakMap@@" + CreateUUID();
            while (HashMap.has(keys, key));
            keys[key] = true;
            return key;
        }

        function GetOrCreateWeakMapTable<K>(target: K, create: true): HashMap<any>;
        function GetOrCreateWeakMapTable<K>(target: K, create: false): HashMap<any> | undefined;
        function GetOrCreateWeakMapTable<K>(target: K, create: boolean): HashMap<any> | undefined {
            if (!hasOwn.call(target, rootKey)) {
                if (!create) return undefined;
                Object.defineProperty(target, rootKey, { value: createDictionary<any>() });
            }
            return (<any>target)[rootKey];
        }

        function FillRandomBytes(buffer: BufferLike, size: number): BufferLike {
            for (let i = 0; i < size; ++i) buffer[i] = Math.random() * 0xff | 0;
            return buffer;
        }

        function GenRandomBytes(size: number): BufferLike {
            if (typeof Uint8Array === "function") {
                if (typeof crypto !== "undefined") return crypto.getRandomValues(new Uint8Array(size)) as Uint8Array;
                if (typeof msCrypto !== "undefined") return msCrypto.getRandomValues(new Uint8Array(size)) as Uint8Array;
                return FillRandomBytes(new Uint8Array(size), size);
            }
            return FillRandomBytes(new Array(size), size);
        }

        function CreateUUID() {
            const data = GenRandomBytes(UUID_SIZE);
            // mark as random - RFC 4122 § 4.4
            data[6] = data[6] & 0x4f | 0x40;
            data[8] = data[8] & 0xbf | 0x80;
            let result = "";
            for (let offset = 0; offset < UUID_SIZE; ++offset) {
                const byte = data[offset];
                if (offset === 4 || offset === 6 || offset === 8) result += "-";
                if (byte < 16) result += "0";
                result += byte.toString(16).toLowerCase();
            }
            return result;
        }
    }

    // uses a heuristic used by v8 and chakra to force an object into dictionary mode.
    function MakeDictionary<T>(obj: T): T {
        (<any>obj).__ = undefined;
        delete (<any>obj).__;
        return obj;
    }

    // patch global Reflect
    (function (__global: any) {
        if (typeof __global.Reflect !== "undefined") {
            if (__global.Reflect !== Reflect) {
                for (const p in Reflect) {
                    if (hasOwn.call(Reflect, p)) {
                        __global.Reflect[p] = (<any>Reflect)[p];
                    }
                }
            }
        }
        else {
            __global.Reflect = Reflect;
        }
    })(
        typeof global !== "undefined" ? global :
            typeof self !== "undefined" ? self :
                Function("return this;")());
//}